#!/usr/bin/env node

const err = console.error,
  log = console.log,
  arg = process.argv[2];
if(typeof(arg)=== 'undefined') {
  err('缺少命令行参数！');
  process.exit(1);
}
if(isNaN(Number(arg))){
  err('命令行参数不是合法数字！');
  process.exit(2);
}
log('退出码:',arg);
process.exit(arg);
